Ball game practice apparatus

ABSTRACT

The invention relates to a ball game practice apparatus, particularly for tennis practice, comprising a ball catching assembly (2) and a ball collecting assembly (3), which in its turn comprises at least a first chute (30) beneath the ball catching assembly, said ball catching assembly being connected with a ball propulsion assembly (5) via a ball feeding assembly (4). A characteristic feature of the invention is that in the ball collecting assembly (3) between the chute (30) and the ball catching assembly (2) there is a damping device (32), through which the balls must pass and which damps the falling speed of the balls to prevent them from leaving the ball collecting assembly (3) by rebounding from the bottom (33) of the chute. Another characteristic feature of the invention is further that the bottom of said at least first chute (30) consists of a plane, preferably sloping only in the longitudinal direction of the chute.

TECHNICAL FIELD

The present invention relates to a ball game practice apparatus,particularly for tennis practice, comprising a ball catching assemblyand a ball collecting assembly, which in turn comprises at least a firstchute beneath the ball catching assembly, the ball catching assemblybeing connected with a ball propulsion assembly via a ball feedingassembly. The balls are propelled from the ball propulsion assembly andare returned by the player towards the ball catching assembly, wherefromthe balls via the ball collecting assembly and the ball propulsionassembly are again forwarded for propulsion.

BACKGROUND ART

A practice device of the kind referred to in the preamble is known fromthe Swedish patent specification No. 366919. This shows a ball catchingassembly connected to a ball feeding assembly, from which balls aredropped down against a rebound surface. The rebound surface is tiltedinwards towards the ball catching assembly, such that a ball which isdropped from above with the aid of the ball feeding assembly will bounceout from the practice apparatus towards the player.

The known ball catching assembly consists of a canvas against which theballs are directed and from which the balls will fall down into a funnelshaped space having an outlet opening. A disadvantage with this knownball catching assembly is that the balls tend to prevent themselves fromfalling down through the outlet opening, towards which opening they rollfrom two opposite directions.

Instead of dropping the balls against a rebound surface it is also knownto propel the balls with the aid of compressed air through a propulsiontube, as is described e.g. in the U.S. Pat. No. 3,584,614 and theEuropean patent specification No. A1 0043886.

Training apparatuses of the type mentioned in the preamble are describedalso in the German patent publication No. 2456997. According to anembodiment shown in FIGS. 2 and 3 the ball collecting assembly consistsof a chute of flexible material and having a rounded bottom. The ballcatching device consists of canvas which directs the balls such thatthey will fall down into the chute. Although the chute consists of aflexible material, it cannot be avoided that balls frequently reboundupwards and out of the chute. Further, balls which follow the rear sideof the chute may roll down with such a speed along the rear side thatthey will proceed up over the front edge and in that way escape from thechute. Another drawback with the rounded design, which has been provedduring the development of the present invention, is that balls can bejammed towards one another and in that way fasten on their route alongthe bottom of the chute towards the feeding-out opening, and thistendency can even be greater if the chute is made of a flexiblematerial. FIGS. 14 and 15 in the German patent publication No. 2456998illustrate another embodiment of a training apparatus according to thepreamble. In this case, it is true that the bottom of the chute isessentially flat, which may prevent said jamming of the balls. In orderto prevent the rebound effect, the bottom of the chute, however, hasbeen made of a network with sufficiently small mesh size in order toprevent the balls from passing through. A material of this type is not agood roll bed for the balls with the result that the balls may beprevented from rolling to the feeding-out opening in the lowest locatedpoint of the chute. Evidently, in order to prevent the balls fromrebounding out from the chute over the net, the chute has also been madevery broad, which is not a good solution, since it would take aconsiderable space from the training court at the same time as thepractice apparatus will be difficult to stow away when it is not in use.

DISCLOSURE OF THE INVENTION

It is an objective of the invention to provide a ball game practiceapparatus which does not have the drawbacks of known ball game practiceapparatuses referred to above. According to a first aspect of theinvention there is a damping device in the ball collecting assemblybetween the chute and the ball catching assembly. The balls have to passthis damping device which reduces their velocity of fall. The dampingdevice also will prevent the balls from escaping from the ballcollecting assembly by rebounding from the bottom of the chute.According to a second aspect of the invention there is a feature of theinvention that the bottom of the chute consists of a flat gradient planeof a comparatively hard and stiff material, and wherein the bottom ofthe chute is inclined preferably only in the longitudinal direction ofthe chute. Preferably the bottom breadth of said at least first, flatchute corresponds to between 3 and 12 ball diameters, preferably tobetween 4 and 10 ball diameters. Ball diameter in this connectionrelates to the diameter of those balls for which the apparatus isdesigned.

According to a preferred embodiment the damping device consists of a netstretched out at a distance above the bottom of the chute, the meshes ofthe net being somewhat but not much wider than the ball diameter. It istherefore unlikely that a ball would fall through the net withouttouching the net. Still less likely is the possibility that a ball wouldrebound from the inclined bottom passing through the net again withoutfirst being damped by touching the net. As a matter of fact thelikelyhood is so small that it can be neglected.

Also other damping devices than nets are in principle conceivable. Amongsuch possibly conceivable devices may be mentioned lines (ropes)stretched out above the chute in the longitudinal direction of the chuteas well as in its transversal direction so that the lines will form anet pattern. Further, one can conceive replacing the net by lamellaewhich extend preferably transversally over the chute, slightly inclinedrelative to the vertical direction.

By preventing rebounds from the collecting assembly by means of thedamping device, which is integrated in the collecting assembly, one hasaccording to the invention got free hands as far as directing the ballsdown into the collecting assembly is concerned. This implies i.a. thatone can allow the balls to drop from the highest level in the catchingassembly down towards the collecting assembly without having to countwith fatal rebounds. Therefore it is convenient that the catchingassembly comprises a wall of comparatively flexible material and thatthis wall has a smaller inclination against the horizontal direction inits upper part than its lower part, wherethrough it can be preventedthat the balls will rebound out from the wall so far that they will missthe collecting assembly below the wall.

A preferred embodiment of the apparatus is further characterized in thatthe first chute runs into a second chute having rounded bottom, that thesecond chute slopes towards a ball feeding-out opening, and that thefirst chute is substantially longer than the second one. Suitable thetwo chutes slopes towards one another such that they meet in the lowestpoint of the collecting assembly where the feeding-out opening in amanner per se is located. The damping device covers also the secondchute.

According to the embodiment a ball accumulator is further providedbetween the feeding-out opening and the ball feeding assembly. This byway of example may consist of an inclined tube. The balls may bepropelled from a propulsion tube by the aid of an air pressure providedby means of an air exhauster via a pressure chamber. The ball feeding-indevice by way of example can be located adjacent to the ball feeding-outopening and may have the form of a turnstile with flexible arms.

Further aspects and characteristic features as well as advantages of theinvention will be apparent from the following description of a preferredembodiment. Reference will be made to the accompanying drawings, inwhich

FIG. 1 is a perspective view of the apparatus, from the right andtowards the front,

FIG. 2 shows, partly schematically, the framework of the apparatus inapproximately the same perspective view,

FIG. 3 shows the collecting assembly of the apparatus in a view from theright and towards the front,

FIG. 4 schematically shows the main parts of the collecting assembly andthe ball catching assembly in a vertical section adjacent to theright-hand side of the apparatus in a direction towards the left-handside of the apparatus,

FIG. 5 shows a detail of the catching assembly and a portion of the ballfeeding-out assembly at a larger scale, and

FIG. 6 shows another part of the ball feeding-out assembly.

DESCRIPTION OF PREFERRED EMBODIMENT

The training apparatus according to the invention has been generallydesignated 1 in the drawings. It consists of the following parts, namelya ball catching assembly 2, FIG. 1, a ball collecting assembly 3, FIG.3, a ball feeding assembly and a ball propulsion assembly 5. Thepractice apparatus 1 is erected on a rack or framework 6, which mainlyconsists of metal sheet and sheet metal profiles. Other parts in theapparatus 1 mainly consists of canvas or other flexible material.

In the framework 6 a lower portion has been designated 7. This consistsof a left-hand and a right-hand side panel 8 and 9, respectively. Fourwheels mounted on the side sheets have been designated 10. A bottomsheet has been designated 11. Vertical posts are mounted in the cornersof the lower portion 7. Mounting posts 12, which can be raised andlowered in the vertical direction extend from the corner posts in thelower portion 7, in which they are telescopically mounted. The mountingposts 12 can be locked in desired position by the aid of knob screwswhich are not shown in the drawings. At the upper end, each mountingpost 12 is provided with a horizontal transverse beam 13 extending at aright angle rearwards. Between the transversal beam 13 there extend twoupper canvas rods, a front canvas rod 14 and a rear canvas rod 15 in thesame horizontal plane. A lower front canvas rod 16 can be telescopicallymoved on the mounting posts 12 via sleeves 17 in the ends of said rod 16and can be locked in desired position by the aid of screws which havenot been shown. A rear, lower canvas rod 18, not visible in FIG. 2, ismounted in the rear part of the lower portion 7 at a level which issomewhat lower than that of the lower front canvas rod 16. Details 12-18constitute the frame-work of the ball catching assembly 2. This consistsof a rear catching canvas 20, a pair of side canvases 21 and a roofcanvas 22. Between the side panels 8 and 9 and under the lower frontcanvas rod 16 there is a lower front catching canvas 23 and ahead ofthis a tennis net 24. Further, there are two wings 25, which alsoconsist of canvas. The wings 25 can hang in the mounting posts 12 bymeans of fastening members which can be put down into the mounting postsfrom above and be pivoted in these posts, so that the wings can beturned to desired angular positions.

The rear catching canvas 20 and the side canvases 21 consist of a finemesh or perforated, comparatively heavy curtain material of the typeused for partition purposes in sport halls. Because air can pass throughthe material the damping effect is improved in spite of the fact thatthe material is heavy.

The side canvases 21 are mounted on the mounting posts 12 such that theywith their front portions extend from the outside around the front sideof the mounting posts 12 and thereafter obliquely rearwards-inwards withportions 27 which are obliquely turned inwards. These portions 27 cancatch balls which may follow the inside of the side canvases 21 towardsthe playing area, a tendency which thus can be prevented by the portions27, such that the balls instead are caught by these portions anddirected down into the ball collecting assembly 3.

The lower portion 7 is a welded construction. In other respects theentire apparatus 1 can be dismantled in order to facilitate transportand storage.

The rear catching canvas 20 is inclined somewhat forwards such thatcaught balls will fall down into the ball collecting assembly 3. 75° isa suitable angle of elevation. High balls may be more difficult todirect down into the collecting assembly 3, as this is comparativelynarrow; according to the embodiment 50 cm. There are a number ofconceivable methods which can solve this problem. For example a valance26 may hang freely down from the angle between the rear catching canvas20 and the roof canvas 22. Alternatively, an upper portion 20' of therear catching canvas may be inclined under a smaller angle of elevationthan the lower main portion of the catching canvas 20. 60° is a suitableangle of elevation for this upper portion 20'.

The ball collecting assembly 3 comprises a first chute 30, a secondchute 31 and a damper in the form of a net 32, which is stretchedhorizontally over the chutes 30, 31 about 12 cm under the upper border28 of the tennis net 24. The upper portion of the tennis net, whichextends beyond the damper, has been designated 29.

The first chute 30 extends from the left-hand side panel 8 in adirection towards the other side panel 9 and has a length correspondingto 2/3 of the distance between the side panels 8 and 9. The second chute31 extends from the right-hand side panel 9 and meets the first chute30. Consequently, it has a length corresponding to 1/3 of the distancebetween the two side panels. The two chutes 30 and 31 are made frommetal sheet and are covered with cloth on the inside. The first chute 30has a flat bottom 33 and flat, inwardly sloping sides 34. The totallength of the first chute 30 is about 2 m with a total drop of about 10cm. The sloping angle thus is about 3°. Both smaller and larger slopingangles can be tolerate. The smallest sloping angle, however, should notbe less than 1° and preferably not less than 2°, while the largestsloping angle should not be larger than 6° and suitably not larger than5°. The total breadth of the chutes 30 and 31 according to theembodiment is about 50 cm.

The bottom 35 of the second chute 31 is rounded. It slopes from theright-hand side panel 9 in a direction towards the first chute 30 undera substantially larger sloping angle than the first chute 30. The totaldrop on a length of 1 m is about 20 cm according to the embodiment. Theangle of inclination thus is about 12°. Generally the bottom of thesecond chute should have an angle of inclination which is 2 a 6 times aslarge as that of the first chute 30. The second chute 31 is terminatedby an end wall 36 beneath the lower edge 37 of the first chute 30. Inthe end wall 36 there is a feeding-out opening 38 for balls and ahead ofthis feeding-out opening there is a feeding-out device in the form of aturnstile 39 with a vertical axis of rotation 40 and with four foldablearms 41 made of rubber. The feeding-out turnstile 39 can be rotated inthe horizontal plane via the rotation axis 40 by means of a motor whichhas not been shown. Preferably the rotation is made oscillating a halfto a whole revolution in each direction.

The net 32 covers the chutes 30 and 31 completely and is stretchedhorizontally over the chutes at a height of about 12 cm above thehighest point of the chutes 30, 31 adjacent to the two side panels 8, 9.The mesh size is somewhat--5 a 10%--larger than the diameter of a tennisball, which means that balls only exceptionally will pass through thenet without touching it.

The feeding-out opening 38 and the turnstile 39 are parts of thefeeding-out assembly, which also includes a ball accumulator in the formof an inclined tube 43, which extends between the feeding-out opening 38and a feeding-out apparatus 44. Further, the feeding-out assemblyincludes an air exhauster (blowing fan) which is connected to thefeeding-out apparatus 44 which will be described more in detail togetherwith the description of the mode of operation of the apparatus.

The propulsion assembly 5, FIG. 2, includes a propulsion tube 50, whichis connected to the feeding-out apparatus 44 via a ball conduit 51. Thepropulsion tube 50 can be pivoted sidewards about a vertical axis on abottom support 52 and can be directed in different elevations againstthe horizontal plane by means of a not shown friction lever on thebottom support 52. The sidewards pivoting movement can be provided bymeans of a crank mechanism 53, which is powered by an electric motor viaa not shown gear wheel. The propulsion tube 50 is connected to the ballconduit 51 via a tube bellow 54. The propulsion tube 50 projects throughan opening in the centre of the lower front catching canvas 23 and acorresponding opening 55 in the tennis net 24. The opening in thecatching canvas 23 is sealed by a funnel-like canvas portion connectedto the rear part of the propulsion tube 50.

The mode of operation of the above described apparatus 1 will now beexplained. Balls are returned in the first place against the rearcatching canvas 20. Balls missing the canvas 20 may be caught by thewings 25, which are angled such that the balls will be directed towardsthe catching canvas or directly into the collecting assembly 3. Ballswhich however do not reach over the tennis net 24 will remain on the"player's half of the court" in the same mode as in normal tennis. Ballswhich however pass over the net 24 will be caught by the ball catchingassembly 2, i.e. by the rear catching canvas 20, the side canvas 21including its obliquely inwardly turned portions 27, the roof canvas 22and the wings 25, such that the caught balls will be directed downtowards the ball collecting assembly 3.

In the ball collecting assembly 3 the balls will first meet thehorizontally stretched damping net 32 which damps the speed of the ballsbefore they pass through the net. The velocity of fall thus has beenreduced when the balls hit the bottom of either the first chute 30 orthe second chute 31 which are both hard. As the chutes are hard, theballs will rebound, although the velocity has been reduced. In the caseof high rebounds, the balls will contact the damping net again, thistime from beneath, but the velocity now as a rule is so low that theballs will not pass through the net once again. The net in other wordsoperates as a "back valve" for tennis balls. If this back valve functionin exceptional cases would not work, so that a ball would rebound backthrough the net 32, one can also under these extraordinary circumstancesexpect that the ball again will fall down upon the net and through it.The balls thus will land either in the first chute 30 or in the secondchute 31. If they land in the latter one, they will quickly collect inits bottom portion. If they on the other hand land in the first chute30, which represents the main part of the breadth of the entireapparatus, they will roll down towards the second chute 31 at aconsiderably slower rate. As this first chute 30 is flat and broad, eachball will follow its own rolling path along the bottom 33 of the chute,which prevents the balls from jamming under their route along the chute30.

All balls therefore sooner or later will collect in the bottom of thebucket shaped chute 31. The oscillating turnstile 39 is provided in thebottom of said chute ahead of the feeding out opening 38. By the aid ofoscillating movement of the turnstile 39 the balls will be fed one byone through the feeding-out opening 38 to the inclined ball tube 43,where 12 to 15 balls can be accumulated as a buffer in the system. Fromthe accumulator tube 43 the balls are forwarded into the feeding-outapparatus 44 via an opening 56 in the side wall of an entrance chamber57, FIG. 6. There the balls land on an intermediate spring partition 58which is provided with longitudinal slots, not shown, in which a latticeshaped pusher means 58 can proceed. The pusher 58 advance the balls oneby one through an opening 60 in the rear wall of a pressure chamber 61,which is supplied with compressed air from the blowing fan 45. The ballpasses a valve 62 and rolls down along a sloping bottom 63, which at thesame time as it slopes downwards also slopes at side towards theright-hand side of the chamber, which is provided with a blowing-outopening 64, to which the ball conduit 51 is connected. By gravitationthe balls are thus directed one by one in the ball conduit 51. As soonas a ball enters the ball conduit 51, a counter-pressure is built up inthe air in the pressure chamber 61, and thereby the valve 62 is shut.The air pressure increases until the ball is brought to move through theball conduit 51, in order to be finally propelled through the propulsiontube 50. A new ball is thereafter brought to the pressure chamber 61 bymeans of a pusher, whereupon the procedure is repeated.

I claim:
 1. A ball game practice apparatus, suitable for tennis practice, said apparatus comprising:a ball catching assembly; a ball collecting assembly comprising first elongated chute means disposed beneath said ball catching assembly, said chute means having a bottom surface; a ball feed means associated with said ball collecting assembly; a ball propulsion assembly connected to said ball collecting assembly via said ball feeding assembly; ball damping means extending between said first chute means and said ball catching assembly for damping the speed of balls and preventing said balls from leaving said ball collecting assembly as a result of rebounding from said bottom surface of said chute means, said chute means conveying balls toward said ball propulsion assembly after passing said damping means.
 2. An apparatus according to claim 1, wherein said bottom surface of said first chute means comprises an inclined gradient plane.
 3. An apparatus according to claim 2, wherein said inclined gradient plane extends longitudinally of said first chute means.
 4. An apparatus according to claim 1, wherein said bottom surface of said first chute means is rigid.
 5. An apparatus according to claim 1, wherein said bottom surface of said first chute means has a breadth which is between 3 and 12 diameters of a regulation tennis ball.
 6. An apparatus according to claim 5, wherein said breadth is between 4 and 12 diameters of a regulation tennis ball.
 7. An apparatus according to claim 1, wherein said ball damping means comprises a net extending over said surface of said first chute means said net having a mesh larger than the diameter of a regulation tennis ball.
 8. An apparatus according to claim 1, wherein said first chute means defines a path which extends towards a second chute means, said second chute extending towards said propulsion assembly for conveying a ball towards said ball propulsion assembly.
 9. An apparatus according to claim 8, wherein said second chute means has arcuate shaped bottom surface.
 10. An apparatus according to claim 8, wherein said propulsion assembly includes a ball projector and said second chute means is inclined towards said ball projector.
 11. An apparatus according to claim 10, and further comprising a ball accumulator disposed between and connected to said ball feed means and said second chute, said feed means being connected to said ball projector for feeding balls thereto one-by-one.
 12. An apparatus according to claim 11, wherein said ball accumulator is a sloping tube.
 13. An apparatus according to claim 11, wherein said ball projector includes a blowing fan connection to a ball collecting chamber and a propulsion tube connected to said chamber, balls being propelled from said propulsion tube by means of air pressure in said chamber produced by said blowing fan.
 14. An apparatus according to claim 11, and further comprising means for feeding balls one by one from said second chute means to said ball accumulator and for feeding balls one by one to said ball feed means.
 15. An apparatus according to claim 8, wherein said first chute means is longer than said second chute means.
 16. An apparatus according to claim 8, wherein said first and second chute means slope in opposite directions and said damping means is above said first and second chute means.
 17. An apparatus according to claim 1, wherein said ball catching assembly comprises an inclined canvas disposed above said ball collecting assembly.
 18. An apparatus according to claim 17, wherein said canvas has an upper portion and a lower portion, means provided on said upper portion of said catching assembly for directing balls which hit said canvas at a high level down towards said collecting assembly. 